Possible padding values:

With this you specify a positive value followed with a unit identifier (it cannot be negative as for the margin).

1

percentage

With this you specify a value with a percentage.
It refer to width of containing block.

1

inherit

Will inherit the value from parent specification. This property value is new with CSS 2.

2

Possible unit identifier:

unit identifier

Comments

CSS

em

The relative unit 'em' is relative to the font size of the element itself.

1

ex

The relative unit 'ex' is relative to the font size of the element itself.

1

px

Pixels, relative to the viewing device

1

in

inches -> 1 inch is equal to 2.54 centimeters.

1

cm

centimeters.

1

mm

millimeters.

1

pt

points -> the points used by CSS2 are equal to 1/72th of an inch.

1

pc

picas -> 1 pica is equal to 12 points.

1

Javascript access:

// To SET values ([o] is the target object)
[o].style.paddingLeft="padding-left value"// To GET values you must first get the computed style object// To get that object in IE or Opera:
var cStyle=[o].currentStyle;
// To get that object in Firefox, Chrome or Safari (w3c-type):
var cStyle=window.getComputedStyle([o],null)
// To GET the property value:;
var value=cStyle.paddingLeft;
// IE and Opera will return a value in units as used with a Set.// Firefox will return a calculated float value in pixel (px).// Chrome or Safari will return a calculated int value in pixel (px).